Pneumatic tool



Patented Dec. 23, 1924.

UNITE HARRY E. ROGERS, OF ST. LOUIS, MISSOURI.

PNEUMATIC TOOL.

Application filed December 27, 1921.

To all whom. t may concern.

Be it known that I, HARRY E. Roenes, a citizen of the United States, residing at the city of St. Louis and State of Missouri, have invented a certain new and useful Improvement in Pneumatic Tools, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, forming part of this application, in which- Figure l is a sectional view through the barrel of a pneumatic hammer showing my improvement embodied therein.

Figure 2 is a top plan view of said barrel.

This invention relates to pneumatic hammers and other pneumatic tools, and particularly to means for lubricating the piston or other moving parts.

One object of my invention is to provide a simple and eflicient lubrication for existing types of pneumatic hammers and which can be incorporated in extant types of hammers now in use.

In the drawings, l indicates the barrel of a pneumatic hammer, and 2 the piston thereof. The handle and controlling valve are indicated in dotted lines, and form no part of my invention.

3 indicates one or more openings drilled lengthwise into the bore of the barrel through its inner end, each of said openings having a port 4 leading into the cylinder chamber at the inner end of the bore 3 and a port 5 leading through the outer end of the bore 3 into said cylinder. Port 4 may be drilled and the port 5 may be filed or formed with a saw kerf.

In practice, a stick or pencil of hard lubricant slightly less in diameter than the bore is introduced into said bore 3, after which the barrel or cylinder is screwed into the handle head which serves to conne the stick of lubricant in position. This lubricant may be hard side rod grease, such as used on locomotives, or tallow, or paraffine mixed with graphite, or any other material having the desired properties and lubricating qualities.

In the ordinary operation of a hammer, the temperature of the barrel is usually rather low on account of the expansion of the compressed air in the cylinder, hence the temperature will not ordinarily rise to such a degree as to melt the lubricant.

Serial No. 525,075.

Then air is admitted at the rear of the piston, and the piston is in the position shown in Figure 1, port 4 will be closed, and the compressed air at the rear of the moving piston will pass through ports' 5 into the space in each chamber 3 around the stick of lubricant. lVhen the piston is advanced to a position in which port 4 will be unsealed, the operating fluid will pass through chamber 3 and port 4 at high velocity and its frictional contact with the lubricant will abrade the latter and particles thereof will pass through port 4 with the fluid.

When the piston reaches the limit of its forward stroke, the ports 4 are opened to the cylinder and when compressed air is admitted to the forward end of the piston for the return stroke and the valve operated so as to permit the air back of the piston to exhaust, the exhausting air passing outward from chambers 3 through ports 4 and 5 carries with it abraded portions of the lubricant, and in exhausting through the valve will carry particles of the lubricant to the valve parts.

The repeated application of fluid pressure to the opposite ends of the piston and the passing of the fluid through chamber 3 in opposite directions will move the stick of lubricant back and forth and further contribute to the abrasive action of the fluid.

The chambers or bores 3 can be cylindrical, as shown, because of the cheapness of producing these openings by the use of a drill, or such chambers may be of any other convenient form. It is important, however, that under working conditions, these chambers shall be closed to the outer atmosphere and open to the bore of the cylinder so that the compressed air can operate upon at least one end of the lubricant in the chamber and the exhaust air draw the lubricant into the chamber to force it to the valve.

What I claim is:

1. A barrel for pneumatic hammers having a lubricating chamber adapted to contain a relatively hard lubricant, said chamber communicating with the bore of the barrel at two different points, one of said points of communication being adapted to remain constantly open, and the other to be opened and closed by the piston in the barrel.

2. A barrel for penumatic hammers having a chamber for lubricants opening through the end of the barrel, said chamber communicating with the bore or piston chamber at a point near the end of the barrel and at another point intermediate the ends of the barrel, the; last mentioned point of communication being` adapted to be alternately opened and closed by the movement of the piston.

3. In a pneumatic tool, a lubricant reser- Voir in the wall ,of the piston chamber, the lubricant reservoir being closed to the outer atmosphere and open to the piston chamber at two different points and containing a lubricant of less Volume than the capacity of said reservoir said lubricant being adapted to be acted upon abrasively by passage of the operating air.

4. In a pneumatic tool, a cylinder7 a reciprocating element therein, a passage in the Wall of said cylinder leading to spaced points on said element to admit fluid under pressure for moving said element and a lubricant in said passage adapted to be abraded and delivered by said fluid to surfaces to be lubricated.

In testimony whereof I hereunto afiix my sig-nature this 16th day of Dec., 1921.

HARRY E. ROGERS. 

